a) Field of the Invention
The present invention relates to a mirror drive unit for tilting a mirror pivotably supported in a mirror housing. In particular, it relates to an improved structure for an electrical connection from a battery to a plurality of mirror-tilting motors housed in a power unit fixed in the mirror housing.
b) Statement of Related Art
In an electrically remote-controlled mirror assembly, a pair of motors for driving a mirror about the horizontal and vertical axes, respectively, thereof is housed in a power unit and the mirror is fixed to a mirror holder and tiltably supported on a ball-and-socket joint provided outside the power unit. The power unit supporting the mirror is housed in a mirror housing forming the profile of the remote-controlled mirror assembly. A pair of plungers or threaded rods to tilt the mirror about the horizontal and vertical axes, respectively, is disposed for a reciprocal movement in relation to the power unit. The forward or reverse revolution of each motor is converted into a forward or backward movement of each plunger through a corresponding reduction gear train, whereby the mirror is tilted about the horizontal and vertical axes, respectively, thereof. The pair of motors which drive the mirror is supplied with power from a battery through a control circuit having a control switch. Generally, the motors and control switch are electrically connected to each other through a plurality of sheathed wires extended from the control switch and of which the ends are introduced into the power unit through through-holes formed in the latter and soldered directly to the output terminals of each motor or soldered to the electrically conductive plates connected to the output terminals. This structure of electrical connection is disadvantageous because soldering is required, which adds to the number of assembling steps.
To overcome such disadvantages, a structure of electrical connection using sockets and connectors has been proposed in which a plurality of conductor pieces electrically connected to the terminals of each motor in the power unit is formed integrally with the power unit to form a socket of which the one end is exposed outside the power unit and in which the ends of a plurality of sheathed wires extended from a control circuit are connected to one connector. Such conventional structures of electrical connection are known from the disclosures in the Japanese Unexamined Utility Model Publication No. 61-204845 and U.S. Pat. No. 4,930,370. However, this structure of electrical connection is disadvantageous in that the connector is easily disconnectable from the socket and that the freedom in design of the mirror housing in which the power unit is provided is limited since the socket protrudes out of the power unit.